Reinforced rotating head for a tunnel boring machine



United States Patent inventor Marcel Montacie Paris, France Appl. No. 776,644 Filed Nov. 18,1968 Patented Dec. 8, 1970 Assignee Union lndustrielle Blanzy-Ouest Paris, France a corporation of FRance Priority Nov. 17, 1967 France No. P.V.128.753

REINFORCED ROTATING HEAD FOR A TUNNEL BORING MACHINE 5 Claims, 5 Drawing Figs.

U.S. Cl 299/56, 175/335, 175/375 299/8 6, 299/90 Int. Cl. .1 E2lb 9/12, E2lc 37/26 [50] Field of Search.....'....'..'. 299/56-.

[56] References Cited UNlTED STATES PATENTS 3,232,670 2/1966 Robbins et al. 299/56 3,237,990 3/1966 Robbins et a1. 299/56 3,285,355 11/1966 Neilson et al 175/334 Primary Exdminer- Ernest R. Purser Attorney-Sughrue, Rothwell, Mion, Zinn & MacPeak ABSTRACT: In a reinforced rotating head for a tunnel-boring machine brackets are welded radially to the exterior to reinforce the structure and to help in the mounting of peripheral tools, at desired locations, along with collecting troughs. Radial and axial forces to which it is subjected are borne separate- 1y, i.e. the former by rollerbearings and the latter by an abutment. I

PATENT ED DEE 81976 SHEET 3 0F 5 1 It is also known to combine the BACKGROUND OF THE INVENTION I Field, of the Invention The present invention relates to a rotating head for a continuous tunnel boring machine and is concerned more particularly with a more rigid reinforced head for heavy duty use, and t of the method of fixing toolson the latter to facilitate their subsequent'dis'mounting for more frequent replacement of said tools, particularly those situated at the periphery where the wear is more rapid. It is also'concerned with the mounting of the head on the front of the machine, whereby, because of the separation of the high axial forces and radial forces to which it is subjected, ensures a longer effective life for the bearings'whic'h absorb such forces.

2. Description of the Prior'Art It is of course known to fix all the peripheral tool holders to an adjusting ring which permits'the inclination of the holders to be varied simultaneously, The lowering of the peripheral tool holders towards the center then permits the replacement of the tool-formingcutters when they become worn; however, first the operation of the adjusting ring requires the use of powerful hydraulic means and second it is necessary to lower vonly the tool holders when it is desired to change the cutter.

The method of mounting the peripheral tool holders on anindividual oscillating shaft permits these to be lowered one by one, according to' the maintenance requirement.

peripheral tool holders with the waste-collecting troughs; however, this hybrid arrangement involves troublesome interdependence of the two parts, which is simultaneously harmful to a good attack on the workin'glface by the cutter and to the suitable collection of the waste 'material. i

SUMMARY OF THE-INVENTION This invention consists in welding to the periphery of the boring head a series of radial, parallel brackets for reinforcing and rigidifying the head and for' mounting the peripheral tool holders, each'in one of'the said pairs of brackets. Some of these latter receive a collecting trough in parallel relation and independently of the corresponding tool holder. In this way, the tool holders are more rigid and the troughs are better disposed, and the independence of the two parts requires only the defective part to be replaced.

The present invention comprises a reinforced rotating head for a machine used in the continuous boring of tunnels. It includes a cylindrical sleeve he'ld'between two coaxial discs, the front disc carrying the tools for attacking the working face, under the combined effect of the rotation of the said head and of a thrust exerted along the said axis, and is characterized in that brackets welded radially to the exterior of the said sleeve reinforce the structure of the latter, and further serve both for fixing the peripheral tool holders, according to their proper inclinations, and for fixing the collecting troughs. The head is mounted for turning movement at the front of the body of the machine by interposition of tworoller bearings and a stop disposed axially of the machine, respectively supporting the radial. forces and the axial forces to which it is subjected.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a partial longitudinal section of a boring head of this invention mounted on its support.

FIG. 2 is a front view of the boring head of FIG. 1 before mounting the tools.

2 DETAILED DESCRIPTION OF THE INVENTION The boring head (F IG.. 1) is essentially formed by a sleeve I held between two plates, which are respectively the front plate 2 and the rear plate 3. In order to ensure the rigidity of the head, the parts I, 2 and 3 are on the one hand made of thick sheet metal while, on the other hand, brackets 4 are disposed regularly on the periphery of the sleeve 1 and are welded both to the latter and to the plate 3, and on the ring 5 extending the plate 2 externally of the sleeve 1.

The front plate 2 (FIGS. 1 and 2) carries, in combination with the-ring 5, the central tools comprising at the center a tricone 6 and then, distributed radially and angularly at the same time, cutters 7 which are mounted on their respective supports called central tool; holders, two of them (8 and 9) being shown in FIG. 1. The tricone is also mounted on a carrier component 10.

Centering holes, namely, and 12 for the six central tool 2 and the ring 5. 1

The tricone holder 10 is centered by being seated and bolted to the plate 2'. 'A conical recessed seating 13 is machined on the front face of the tricone holder 10 and this receives the conical projectingportion 14 on the tricone. A key interposed between the two parts of this connection prevents any rotation of one part relatively to the other, while their mutual fixing is effected by at least three bolts respectively arranged in thespaces left free between the boring cones 15. l

The arrangement of this tricone in two parts facilitates the changing of the latter'when it is worn. while the known tricone for petroleum drilling with a-threaded rear part and used hitherto in underground drilling operations was particularly difficult to remove because of the lack of space inside a gallery for the positioning and maneuvering of the lever arm providing the high torque necessary for the loosening operation.

The longitudinal section (FIG. 3) of the working face, along a plane passing through the axis of rotation of the boring head, is shown in the form of a curve 15 passing by the ends of the straight arrowheaded lines, such as 20. The position of each straight line represents the inclination relatively to the axis of rotation of the cutting plane of each corresponding cutter when the axis of rotation of these latter cutters, 'during the rotation of the head, is in the plane of the said section and the end of the arrow then represents the point of contact of the cutter with the working face. At this moment, the six straight lines bearing the references 16 to 21 show the inclinations of the planes of symmetry'of the. six central cutters which, by

holes 11 for the tricone carrier holders, are formed in the plate their position combined with'that of the tricone 6, of which the points of contact (not shown) with the section 15 would be situated below the line 16, thus ensure the rectilinear part of the section 15, that is to say, ensure a plane and central circular part for the working face.

The central tool holders (FIG. 4) are cut from a solid. They comprise a trued base22 that they can be fixed by Two bearings 24 and 25 receive the shaft 26, around which the cutter 7 turns freely. The bearing caps 27 are formed of flat metal plates which are shaped by pressing and each of them carries a stud 28 which, on assembly, extends into a corresponding hole 29 in the shaft so as to prevent the latter from turning. The tightening of the bearing caps on their support is effected by intermediate parts 30. The angle 31 of the trued plane of the base relative to the plane 32 before trueing as shown in broken lines is equal to the angle which is made by the cutting plane of the cutter 7 with the axis of rotation of the head, that is to say, it is equal to that of the arrowheaded straight line corresponding with the axis of rotation of the boring head.

Therefore, corresponding to the straight lines 16 and 17 perpendicularto the plane of the working face are two cutters with a cutting plane parallel to the axis or rotation of the borformed with a series of holes 23 so means of bolts on the boring head.

ing -head, while the following cutters assume an increasing inclination in a direction away from the axis of rotation of the said head. The arrowheaded straight line 21 then corresponds to the cutter with its central support furthest'from the axis.

The inclination ofa cutter with a central support is thus obtained, once and for all, in manufacture, while its position on the boring head is achieved 'at the time of assembly, by means of a central hole 33 formed in the base of the central tool holder which is caused to coincide with the corresponding hole 12 of the front face of the head (FIG. 2). A thick disc is shaped for this purpose and forms a key between the two parts. The final orientation of the cutter is then obtained by causing the axis of the corresponding shaft 26 of the cutter to meet the axis ofrotation ofthe boring head. The peripheral tool holders 34 (FIG. I and HO. are all identical, each cut from a solid in order to form a steel component of constant thickness, carrying at its base two holes 35 and 36 and in its upper part two bearings on which rest the fixed shaft 26 on which the cutter 7 turns freely. The locking of the shaft 26 is effected in'the same way as with the central cutters, by means of studs '28 mounted on the caps 37 and extending into the corresponding holes of the said shaft.

The hole 35 receives a pivot spindle bearing on the corresponding holes of the two parallel brackets 4 supporting the tool holder 34 and permits the latter to be easily inclined towards the center for changing a cutter 7 when it is worn. The

hole 36 serves for the introduction of a spindle for fixing the cutter 7 after the latter has been adjusted to the required inclination.

The inclination (FlG. 3)of eight peripheral cutters is shown by the .arrowheaded straight lines 38 to 45. After having arranged a peripheral tool holder 34 for oscillation about its spindle fitted in the hole 35 and adjusting the cutter 7 to the required inclination, holes coaxial with and of the same diameter as the hole 36 are cut in the brackets 4. A cylindrical pin of required diameter is then introduced into the series of holes as thus drilled in order to maintain the adjustment ofthe cutter 7.

As shown in FIG. 3, the eight peripheral cutters are distributed in such a way as to prolong the rectilinear part of the longitudinal section'l5 of the tunnel by an arc ofa circle, centered on the pivot axis of the peripheral tool holders, that is to say, on the center of the hole 35.

The eight peripheral tool holders rest on eight pairs of parallel brackets 4 (FIG; 2). On the other hand, to the rear of the peripheral tool holders, there are arranged waste collecting troughs 46 which are each fixed on two parallel brackets 4. The troughs, which are four in number, are regularly arranged, both the peripheral tool holders behind the least inclined of them, and the bracket of each pair of trough-carrying brackets, situated in front in the direction of rotation of the boring head, has a rectangular opening 47 facilitating the entry of the rock waste; this waste, as the trough passes through its top position, traverses the hole 48 formed in the sleeve 1 between the brackets 4 perpendicularly of the said trough and drops into a chain conveyor, of which the framework 49 is used for reinforcing the structure of the support in front ofthe boring head.

The boring head is a rigid structure, of which all the parts are welded, except the front plate 2, which is assembled by being machined to size and fixed on the sleeve by anchor bolts (not shown), which are screwed into the-tapped holes 50.

The head is driven in rotation by an internally toothed ring 51 fixed to the rear of the said head on the plate 3 by bolts screwed into the tapped holes 52.

The boring head rests on the front of the machine by means of two coaxial cylindrical roller bearings defining the axis of rotation thereof. The first bearing, of relatively'small dimensions, is disposed in front. The movable inside race '55 of the latter is fixed to the rear of the tricone holding part 10, while the fixed external race 56 is held on the disc 57, forming the front of the machine structure, by means of a ring 58 welded on the latter.

The second roller bearing 54, of a larger diameter than the diameter of the first bearing, is disposed at the rear ofthe boring head: its movable inner race 59 rests in a seating machined on the outside of the toothed wheel 51, while its fixed external race 60 is seated in a shoulder of the plate 62 of the fixed structure of the machine. H v

The external race 60 also serves as a stop ring fixed to the axial abutment 62 of large diametei ahd with cylindrical rollers bearing on the other side against a movable ring 63 incontact with the plate 3 of the boring head and tttthsmitth 'gthe thrust being exerted on the latter duringthe boringoperation.

In order to complete the fixing of the boring hea d,'=a counter-abutment 64 disposed at the front in the vicinityuof the bearing 53 ensures, that the said head is held inposition when the latter is not in contact with the working face, that. is

' to say, during rest periods or tool-changing periods.-

The distribution of the radial and axial thrusts, assured respectively and separately by the bearings 53 and 54 and-the abutment 62, ensuresthat these parts have a longer life; however, in order to maintain such an advantage of resistance to wear, it is in addition necessary to protect these same parts from the abrasive dust which results from the boring operation. For this purpose, three sealing arrangements are positioned between the movable head and its fixed support. At the front, the bearing 53 and the counter-abutment 64 are protected by the device comprising a toroidal elastic joint '65. At the rear, the annular device 66 connected to the plate 3-ensures, by interposition of lip joints 67 between the plate 3 and the periphery of the plate 61, the tightness of the oil lubrication system for the toothed wheel drive 51, the bearing 54 and the abutment 62. Finally, the hard friction joint 68, while participating in the oil tightness of the foregoing system, eliminates the dust resulting from the dropping through .the orifices 48 of the waste material transported by the troughs 46 and transferred by chain conveyor (not shown) to the rear of the fixed structure, the illustration of which has ended just after the plate 69.

It has to be understood that the present description, which has only been given by way of example, has no limiting character and that it is possible to effect numerous modifications in the details of assembly and also in the combination and disposition of the elements without departing from the field of application or from the principles of the present invention.

Thus, the number of pairs of brackets corresponding to the number of peripheral tools can be modified while maintaining the regularity of the longitudinal profile 15 of the working face and without the reaction of the latter on the boring head being spaced from the immediate ,vicinity of the axis of rotation thereof.

' Similarly, the mounting ofa peripheral tool holder between two parallel brackets on a pivot spindle and with locking pin-in position can be effected in any other equivalent manner which guarantees the unity of pattern of the peripheral tool holders.

- and means including two bearings and an abutment for centering and supporting said rotating head for rotation about'its axis, the improvement comprising: circumferentiallyspaced, a radial brackets welded to the outside ofsaid outside surface of said sleeve anindividual, identical peripheral tool holders and collecting troughs fixed to respective brackets.

2. The rotating head as claimed in claim 1 whereinsaid bearings comprise roller bearings, and said head further comprises means including the fixed outerv race of the'rear roller bearing defining an axial abutment ring.

3. The rotating head as claimed in claim 1 further comprising means coupled to the rear plate for rotationally driving I wherein said brackets comprise radial plates carrying spaced holes therein, said peripheral tool holders comprise plates lation of said tool holder with respect to said bracket and said having similarly placed holes, and said tool holders and said head further include a pin extending through aligned holes of said tool holder and saidbracket for defining the axis of oscilother aligned holes carrya bolt for locking said tool holder in the required angular position on said radial bracket.

5 The rotating head as claimed in claim 4 wherein said hole for receiving the pin of said tool holder. is drilled coaxially within the corresponding bracket after adjustment of the peripheral tool holder to the required angle of inclination of the cutter carried thereby. v 

